Understanding Shaking Hands After Tool Use: Muscle Fatigue or Injury?

Question
My friend was cutting down some thorn bushes with a very powerful and heavy "weed wacker" sort of tool. It was heavy and hard to control so he was holding it very tightly to try to keep it steady. It and he were shaking while he was operating it.  That night his hands and legs were numb and shaky. His hands were still shaky the next morning. Is it possible he did some kind of damage to himself?

Answer
Hi Barbara,
Not likely. The shaking just represents muscle fatigue. As for the tingling, the vibrations can cause a temporary neurapraxia (a dysfunction of the nerve). The three main nerves in the arm come together in the hand, all three being on the palm side. This should pass in time as will the shakiness. Next time around he should use a less heavy weed cutting device and wear gloves to absorb the vibrations (taken from my own experience!).